To study the photosynthetic mechanism of submergence resistance in peach rootstocks,we studied the effects of water-logging on photosynthetic characteristics of peach rootstock seedlings ［Maotao (Prunus persica (L.) Batsch.),Shantao (P.davidiana (Carr.) Franch.)］ and Nemaguard with normal water supply as control.The results showed that net photosynthetic rate(P_n),relative water content(RWC),water use efficiency(WUE),transpiration rate(T_r),stomatal conductance(G_s),apparent quantum yield(AQY),carboxylation efficiency(CE) and maximal photosynthetic electron transport rate(J_max) in leaves were significantly lower than control,but the MDA content was opposite.Nemaguard had higher chlorophyll content under submergence stress in the late experiment period.Meanwhile,decrease amplitude of P_n,RWC,T_r,WUE and G_s of Nemaguard were the lowest among the 3 cultivars,Maotao took second place.The level of water-logging tolerance among the 3 peach rootstock seedlings was Nemaguard>Maotao>Shantao.As response to water-logging,membrane-lipid peroxidation was intensified,the stomatal aperture,water metabolism capacity,photosynthetic electron transport rate and photosynthetic capacity decreased.The chlorophyll biosynthesis of Nemaguard under water-logging enhanced and descending speed of RWC were slower,which led to higher light absorption and water metabolism capacity;Nemaguard had stronger resistance to photoinhibition and photooxidation because of the lowest membrane lipid peroxide level,there for,Nemaguard could keep the highest photosynthetic capacity among the 3 peach rootstock seedlings.